Centrifuge construction



NOV. 10, 1936. PELTZER 2,060,239

GENTRIFUGE CQNSTRUCTION Filed July 2, 1934 s Sheets-Sheet 1 INVENTOR.

' H/zr/ Pe/zzzr ATTORNEY NOV. 10, 1936. PELTZER 2,060,239

CENTRIFUGE CONSTRUCTION Filed July 2, 1934 3 Sheets-Sheet 2 F IE -7 4INVENTOR. 4/fier/ Pe/fzer ATTORNEY Nov. 10, 1936. A. PELTZER 2,050,239

CENTRIFUGE CONSTRUCTION I Filed July 2, 19:54 :5 Sheets-Shee t s Ex 33J4 M 11 NTOR. I A/er/ Pe/ zr ATTORNEY Patented Nov. 10, 1936 UNITEDSTATES 2,060,239 CENTBIFUGE CONSTRUCTION Albert ream, Palo Alto, Calif.,assignor to Merco' Centrifugal Separator Co. Ltd., San Francisco,Calif., a corporation of California Application July 2, 1934, Serial No.133,446

scm s. (01. 233- 47) a This invention relates generally to machines vfor the centrifugal separation of heavier and lighter components of afluid feed material. It is concemed particularly with the constructionof the nozzles utilized for ,the discharge of the heavier separatedmaterial.

It is an object of the invention to provide a 1 nozzle construction forcentrifuge machines, which will minimize power losses, which will havea-relatively long, useful life, and which may be replaced in the eventof, undue wear.

A further object is to provide a centrifuge nozzle which can have onlyone position with respect to the rotor, thereby avoiding improperapplication.

A further object of the invention is to provide a nozzle which willafford a means for controlling the capacity of the machine and thevelocity of discharge.

Another object of the invention is to provide a nozzle construction andarrangement which will avoid undue wear upon the advancing faces of theprojecting nozzle portions.

- Further objects of the invention will appear from the followingdescription in which the preferred embodiment of the invention has beenset 'forth in detail in conjunction with the accompanying drawings. i

Referring to the drawings:

Fig. 1 is aside elevational detail, in cross-section, showing a portionof. a centrifuge machine with my nozzle construction applied thereto.

Fig. 2 is an end view of the nozzle construction shown incorporated, inthe machine of Fig. 1. Fig. 3 is a cross-sectional detail taken alongthe 'line3IofFig.2.- Fig.4 is a cross-sectional detail, taken along theline 4-4 of Fig. 2.

Fig. 5 is a view similar to Flg. 4,'but showing a modified type ofnozzle.

Fig. 6 is a cross-sectional detail showing a further modified nozzlehaving a separate wearing head.

- Fig. 7. is a view looking toward the outer. end

of the nozzle shown in Fig. 6.

Fig. 8 is a cross-sectional detail showing another modified nozzlehaving a' separate wearing head. I

Fig. 9 is a view looking toward the end of the nozzle shown in Fig. 8.

Fig. 10 is a side elevational view showing a part of the centrifugerotor, and illustrating a further modification.

Fig. 11 is a view similar to Fig. 2, but likewise showing a furthermodification.

Fig. His a cross-sectional detail similar to Fig. 1, showing the desiredrelationship between the jetting from the nozzles and the volute.

The portion of the centrifuge machine illus-' trated in Fig. 1 is inaccordance with the'ma- 5 chine disclosed in United States Patent No.

1,923,455, dated August 22, 1933. In a machine ofthis character, only aportion of the underflow, or heavier separated material, is removed forfinal delivery, while the remainder is con- 10 tinuously returned intothe centrifuge rotor. Briefly, the machine consists of a rotor I 0,carried by a rotatable shaft ll. ,Feed material is introduced into therotor through passage l2,

lighter separated material is discharged over wier 15 I3, and heavierseparated material or underflow is discharged from thecircumferentially-spaced nozzles l4; Surrounding the rotor 10 there is avolute structure It, which is formed with an annular chamber I'l forreceiving the material discharged from nozzles I l. A part of theheavier material or underflow discharged into chamber "is removed forfinal delivery, and the remainder is returned, by way of passages l8,conduit l9, and ducts 2 I, to the outer portion of the inner rotorchamber23.

With a centrifuge such as described above, it is evident that arelatively large quantity 'of materialis discharged intochamber l1, andsince the nozzles M are disposed on the periphery of 30 the rotor, theyare subjected to relatively high fluid pressures. As the underfiowmaterial is,

. discharged from the nozzles H, a certain amount of splattering occurs,and splattered particles are therefore encountered by projectingportions 35 of the nozzles during their rotation. Likewise, a nozzle inits rotation may be impacted with material discharged from a precedingnozzle, before such material has had an opportunity to clear the path ofrotation of the nozzles. It has been found that the impact of dischargedparticles upon the projecting portions of nozzles I may absorb amaterial amount of power and cause considerable wear. I

, Referring now to the articular nozzie-con- 45 struction illustrated ins. 2 to 4 inclusive, the

construction shown therein consists of a body 28, which is ported forflow of fluid material therethrough, as will be presently explained. Theenlarged cylindrical portion 21 of ody 26 is 50 adapted to snugly fitwithin a mac ned opening 'in the outer wall of the oentrifug rotor. Amachined shoulder28, formed upon the inner end of the nozzle body,serves to seat upon a similar shoulder formed in the rotor, thusretaining the 55 The enlarged portion 21 of the nozzle body is providedwith a cylindrical passage 32 which communicates with the interior ofthe rotor. Leading from passage 32 there is a cylindrical bore 33 ofreduced diameter, which is offset from the general axis of the nozzle,as is apparent from Figs. 2 and 4. Communicating with the outer end ofbore 33, there is a final discharge port 34 which opens through thetrailing face 3i of the nozzle portion 29.

Generally, the centrifuge bowl is provided with a plurality of nozzlesas described above. The positioning of these nozzles is such that, withrespect to the direction of rotation, ports 34 deliver materialbackwardly from the trailing nozzle faces 3i. The body of the rotor hasa lip 36 surrounding the portion 29 of each nozzle, with an openingtherein corresponding to the oval contour shown in Fig. 2. Therefore,each nozzle can be placed in only one position with respect to therotor, with the discharge port 34 directed backwardly and in the planeof rotation.

It has been found that with nozzles of this character a minimum amountof power loss is contacting the particles. The offset positioning ofpassage 33 makes possible a relatively large amount of metal surroundingthe port 34, thus insuring good wearing properties.

No special securing means is required for retaining nozzles of the abovetype in proper position with respect to the rotor, since they are heldin tight engagement with the rotor through centrifugal force and throughthe pressure of fluid material within the rotor. However, upondismantling the rotor, the nozzles can be readily removed forreplacement.

In Fig. 5 there is shown a modified type of nozzle made oi. a coredcasting in place of .the usual machined metal. In this case, the passagev 31 is of graduallyreduced cross-sectional area to the discharge port38, and all corners are rounded to aflord a minimum of flow resistance.

With such a construction the external head portion 29 may wear away to aconsiderable extent,

by impact' with discharged particles, without Likewise, the tapered bendto passage 31 minimizes internal wearing away of metal. I have alsoshown, in,

conjunction with this modification, a fiow choke or attenuating member39. This member is snugly fitted into the inner end of thenozzle,

and is provided with a control port "4|. with such a member usedtogether with the nozzle,

the rate of discharge from port 38 is reduced, somewhat, dependent uponthe size of port -4l,

and the underflow discharge capacity of the machine is somewhat reduced,without, however,

reducing the diameter of port 38. "This'efiect is deemed due toturbulence in the enlarged space between ports '38 and 4i, which absorbsconsiderable energy from the flowing material.

Even with the nozzle described above, impact of the outer head portionsof the nozzles with particles of discharged material may cause such anamount of wear as to necessitate replacement before other surfaces havebeen worn away to a detrimental degree. Therefore, in some instances itis desirable to employ a separate wearing head. such as is incorporatedin the nozzles of Figs. 6 to 9 inclusive. In the modification of Figs. 6and 7, the nozzle body is formed of two parts 43 and 44, part 43 beingin the form of a ported shank, and part being in the form of an externalwearing head. These parts are secured together by a threaded connection48, and afford a fiow passage 41 to the backwardly directed dischargeport 48. In order to minimize wear, the discharge port ,may be providedwith a wear resisting liner 49, such as a hard tungsten alloy. As viewedin Fig. '7, the head is ovaloid in contour and its base is seated withina similarly contoured recess 5| formed in the rotor periphery. Theexternal surfaces of the head are rounded or stream-lined, to afford aminimum amount of power loss and to minimize wear by impact withdischarged particles. Such a head affords a relatively large amount ofmetal which is available for receiving wear, before the head requiresreplacement.

The modification of Figs. 8 and 9 is similar to that shown in Figs. 6and 7, in that a separate external wearing head is likewise provided. Inthis instance, the shank 53 is of greater length and has a threadedconnection 56 with the head 54; Instead of forming a discharge portdirectly in the head, a separate fitting 51 is provided,

which has a discharge port 58 communicating with the flow passage 59.Fitting 51 is received by an opening Si in the advancing side of thehead and is threaded into the outer end of the 'shank, thus affording aninterlocking assembly. The port 58 is shown provided with a wearresisting line 62, such as a glass tube. The head 54 is shaped generallysimilar to the head 44 of Figs. 6 and '7, and is seated within a reccss63 formed in the periphery of the rotor. With such a construction thefitting 51 can be separately replaced in the event the port 58 becomesunduly worn, and the head 54 can be likewise removed for replacement.

As has been previously mentioned, a nozzle in its rotation may impactmaterial discharged from a preceding nozzle or nozzles, to causeconsiderable wear and power absorption. To minimize this difliculty, andalso to avoid a spilling of material over the walls of volute I1, I haveprovided the modification of Figs. 10 to 12 inclusive. In this case thenozzles I4, mounted upon the peripheral wall of rotor I 0, aresubstantially of the form shown in Figs. 1 to 4 inclusive. However,instead of having the center lines 86 of 1 ports 34 in the plane ofrotation of the rotor (indicated by line 61) the ports are directeddownwardly at a slight angle a of say 2% to 5%. Thus the material as itis discharged from a nozzle is caused to mote downwardly out of the pathof a succeeding nozzle or nozzles. As shown vin Fig. 12, the arrangementshould be such that the discharged material, which has considerableradial velocity, strikes the body of the material in volute I! over suchan annular area that there is no spill from this body over either theupper or lower volute walls. In other words, such annular area shouldcoincide generally with the medial plane or the volute, as indicated inFig. 12. 'Iithe discharged material were to strike the body of materialin the volute over an annular area near the upper volute wall, resultingswirls would cause a spill over the lower volute lip. For

' a'particular installation and assembly the angle a should be such asto secure the results mentioned, namely, to minimize wear upon theprotruding portions of the nozzles and to avoid spilling from thevolute.

I claim: I

1. In a nozzle construction for use with centrifuge rotors, abodyadapted to be mounted upon a centrifuge rotor and being ported forfiow of material therethrough, the body having an external head whichprovides a final discharge port directed backwardly relative to thedirection of rotation and which presents rounded surfaces, the leadingface of the head being of reduced width compared to the trailing face.

2. In a nozzle construction for use with centrifuge rotors, a bodyhaving one portion thereof adapted to be mounted in one wall ofacentrifuge rotor and another portion thereof adapted to extend outwardlybeyond the rotor, the advancing face of said extended portion being offinally discharge material from said trailing face.

3.'In a nozzle construction for centrifuge rotors, a two-part body, onepart constituting a shank extending through one wall of the rotor andthe other part constituting an outer head,

means for removably securing the head to the shank, land a backwardlydirected final discharge port provided by the head, the rotor having arecess in which the inner face of the head is seated.

4. In a nozzle construction for centrifuge rotors, atwo-part body, onepart constituting a shank extending through one wall of the rotor andthe other part constituting an outer head, means for removably securingthe head to the shank, and a separate fitting removably secured to thehead and forming a final discharge port, said fitting being interlockedwith the shank.

5. In a centrifuge having means for receivin heavier separated materialfrom a rotor, a plurality of circumferentially spaced nozzles carried bythe rotor for the delivery of heavier separated material, the finaldischarge ports being directed backwardly with respect to the directionof rotation of the rotor and at an inclination with respect to the planeof rotation.

6. In a centrifuge, an annular volute for receiving heavier separatedmaterial from a rotor, and a plurality of circumferentially spacednozzles carried by the rotor for the delivery of heavier separatedmaterial, the final discharge ports of the nozzles being directedbackwardly with respect to the direction of rotation of'the rotor and atan inclination with respect to the plane of rotation, the volute beingso disposed with respect to the nozzles as to avoid spilling over thewalls thereof.

7 ,7. In a nozzle construction for-centrifuge rotors, a two-part body,one part constituting a shank extending through one wall of the rotorand the other part constituting an outer head in which the outer endportion of the shank is socketed, and a separate fitting secured withinan opening in the head and forming afinal discharge port, said fittinghaving its inner end portion interlocked with the outer end portion ofthe shank.

8. In a nozzle construction for use with centrifuge rotors, a bodyadapted to be mounted upon a centrifuge rotor and being ported for flowof material therethrough, the body having a shank discharge portdirected backwardly relative to the direction of rotation, the leadingface of the head portion being of reduced .width compared to r thetrailing face thereof.

ALBERT PELTZER.

